Problem Installing Win7 x86 - Missing Drivers

You mention a "Compatible" setting. What are the other choices there?

i) Disabled
ii) Compatible
iii) Enhanced

Update - Am I allowed to cite a few choice expletives at this moment in time please?

I would study the Manual to fully understand each of those settings as it may hold the key to the install blockage. Something is keeping the installer from seeing the drive.

What is the exact error when you attempt to boot both the Win7 and Vista installer now?

There are a few steps given which haven't been tried so get those out of the way now.

In addition you tried writing the install ISO to flash stick? If it's a retail CD you can install UltraISO trial version, on File tab Open DVD (or ISO if it's burned from a file), on Bootable tab select Write DIsk Image, Format, Write. Boot under HD's or USB.

If it's an ISO you downloaded, confirm integrity and burn another using ImgBUrn at 4x speed with Verify.

We have other tricks up our sleeve but these are the first steps which all need to be tried.